Sublingual buprenorphine spray

ABSTRACT

The invention provides sublingual formulations containing buprenorphine, a pharmaceutically acceptable salt thereof, or a derivative thereof. The invention further provides sublingual formulations containing buprenorphine and naloxone, pharmaceutically acceptable salts thereof or derivatives thereof. The invention further provides a method of treating pain or opioid dependence by administering sublingual formulations containing buprenorphine, a pharmaceutically acceptable salt thereof, or a derivative thereof to a patient in need thereof.

FIELD OF THE INVENTION

The invention is directed to sublingual spray formulations containing buprenorphine, a pharmaceutically acceptable salt thereof, or a derivative thereof. The invention is further directed to sublingual spray formulations containing buprenorphine and naloxone, pharmaceutically acceptable salts thereof or derivatives thereof. The invention is further directed to a method of treating pain or opioid dependence by administering sublingual spray formulations containing buprenorphine or buprenorphine and naloxone, pharmaceutically acceptable salts thereof, or derivatives thereof to a patient in need thereof.

BACKGROUND OF THE INVENTION

Buprenorphine is a semi-synthetic opioid and a partial t-opioid receptor agonist and has the following structure:

Activation of the g-opioid receptor leads to antinociception and is the pathway by which opioids such as morphine and fentanyl reduce acute and chronic pain. Buprenorphine has advantages over other opioids such as morphine and fentanyl in that it is only a partial instead of a full agonist of the opioid receptor-like receptor 1 (“ORL1”). Activation of ORL1 has been reported to weaken the analgesic effect induced by the activation of the μ-opioid receptor. Additionally, buprenorphine is an antagonist of δ- and κ-opioid receptors, whose activation has anti-analgesic and psychotomimetic effects, respectively. Buprenorphine is also useful in the management of opioid dependence. The slow binding of buprenorphine to the μ-opioid receptor along with its strong affinity allows for pain management at relatively low blood concentrations and the slow disassociation of buprenorphine from the μ-opioid receptor results in a lack of withdrawal symptoms.

Buprenorphine is currently available in transdermal patches, intravenous injection, tablet and film strip formulations. Commercially available buprenorphine formulations include Butrans® (Butrans is a registered trademark of Purdue Pharma L.P.), a 7 day transdermal patch that releases buprenorphine at 5, 10 or 20 mcg/hr, and Temgesic, a 0.2 mg sublingual tablet, are used for the treatment of chronic pain. Buprenex® (Buprenex is a registered trademark of Reckitt Benckiser Healthcare (UK) Limited) is a 0.3 mg/mL injectable solution used for the treatment of acute pain. Subutex® (Subutex is a registered trademark of Reckitt Benckiser Healthcare (UK) Limited) and Suboxone® (Suboxone is a registered trademark of Reckitt Benckiser Healthcare (UK) Limited) are tablets used in the treatment of opioid dependence. Subutex® is available in 2 mg and 8 mg sublingual doses of buprenorphine. Suboxone® contains both buprenorphine and naloxone in a 4:1 ratio. Suboxone® is available in tablet form in 2 mg and 8 mg doses. Suboxone® is also available in a sublingual film strip formulation that dissolves faster and is not lost by accidental swallowing.

Naloxone has the following structure and is synthesized from thebaine:

Naloxone is most commonly used to treat patients suffering from opioid dependence or overdose because it is a competitive μ-opioid antagonist that blocks the effects of opioids.

While there are various formulations currently available, there exists a need in the art for a sublingual spray formulation containing buprenorphine or buprenorphine and naloxone, pharmaceutically acceptable salts thereof, or derivatives thereof. Such a formulation should be safe, be easy to administer, have a high bioavailability, and be storage stable.

SUMMARY OF THE INVENTION

In certain embodiments, the present invention is directed to a sublingual spray formulation comprising an effective amount of buprenorphine, a pharmaceutically acceptable salt thereof, or a derivative thereof, water as a solvent, and a mixture of an alcohol and a glycol as a cosolvent.

In certain embodiments, the present invention is directed to a sublingual spray formulation comprising:

-   -   an effective amount of buprenorphine, a pharmaceutically         acceptable salt thereof, or a derivative thereof;     -   naloxone, a pharmaceutically acceptable salt thereof, or a         derivative thereof;     -   water as a solvent; and     -   a mixture of an alcohol and a glycol as a cosolvent.

In certain embodiments, the present invention is directed to a sublingual spray formulation comprising an effective amount of buprenorphine, a pharmaceutically acceptable salt thereof, or a derivative thereof wherein the formulation has a pH from about 3.5 to about 5.5.

In certain embodiments, the present invention is directed to a sublingual spray formulation comprising:

-   -   an effective amount of buprenorphine, a pharmaceutically         acceptable salt thereof, or a derivative thereof;     -   water as a solvent;     -   a mixture of an alcohol and a glycol as a cosolvent; and     -   an antioxidant.

In certain embodiments, the present invention is directed to a sublingual spray formulation comprising:

-   -   an effective amount of buprenorphine, a pharmaceutically         acceptable salt thereof, or a derivative thereof;     -   water as a solvent;     -   a cosolvent selected from the group consisting of an alcohol and         a glycol or a mixture thereof; and     -   an antioxidant

In certain embodiments, the present invention is directed to a sublingual spray formulation comprising:

-   -   an effective amount of buprenorphine, a pharmaceutically         acceptable salt thereof, or a derivative thereof;     -   water as a solvent;     -   a cosolvent selected from the group consisting of an alcohol and         a glycol or a mixture thereof; and     -   an antioxidant.

In certain embodiments, the present invention is directed to a sublingual spray formulation comprising:

-   -   an effective amount of buprenorphine, a pharmaceutically         acceptable salt thereof, or a derivative thereof;     -   water as a solvent;     -   a mixture of an alcohol and a glycol as a cosolvent; and     -   an antioxidant selected from the group consisting of butylated         hydroxyanisole (“BHA”), butylated hydroxytoluene (“BHT”),         methionine, sodium ascorbate, sodium thiosulfate, thioglycerol,         cysteine hydrochloride monohydrate and a mixture thereof.

In certain embodiments, the present invention is directed to a sublingual spray formulation comprising:

-   -   an effective amount of buprenorphine, a pharmaceutically         acceptable salt thereof, or a derivative thereof;     -   water as a solvent;     -   a mixture of ethanol and propylene glycol as a cosolvent; and     -   an antioxidant selected from the group consisting of BHA, BHT,         methionine, sodium ascorbate, sodium thiosulfate and         thioglycerol, cysteine hydrochloride monohydrate or a mixture         thereof.

In certain embodiments, the present invention is directed to a sublingual spray formulation comprising:

-   -   an effective amount of buprenorphine, a pharmaceutically         acceptable salt thereof, or a derivative thereof;     -   water as a cosolvent;     -   a cosolvent selected from the group consisting of ethanol,         propylene glycol, and a mixture thereof;     -   an antioxidant selected from the group consisting of BHA, BHT,         methionine, sodium ascorbate, sodium thiosulfate, thioglycerol,         cysteine hydrochloride monohydrate and a mixture thereof; and     -   a permeation enhancer.

In certain embodiments, the present invention is directed to a sublingual spray formulation comprising:

-   -   an effective amount of buprenorphine, a pharmaceutically         acceptable salt thereof, or a derivative thereof;     -   water as a solvent;     -   a cosolvent selected from the group consisting of ethanol,         propylene glycol, and a mixture thereof;     -   an antioxidant selected from the group consisting of BHA, BHT,         methionine, sodium ascorbate, sodium thiosulfate, thioglycerol,         cysteine hydrochloride monohydrate and a mixture thereof; and     -   menthol as a permeation enhancer.

In certain embodiments, the present invention is directed to a sublingual spray formulation comprising:

-   -   an effective amount of buprenorphine, a pharmaceutically         acceptable salt thereof, or a derivative thereof;     -   water as a solvent;     -   a cosolvent selected from the group consisting of ethanol,         propylene glycol, and a mixture thereof;     -   an antioxidant selected from the group consisting of BHA, BHT,         methionine, sodium ascorbate, sodium thiosulfate, thioglycerol,         cysteine hydrochloride monohydrate and a mixture thereof; and     -   a pH adjustor.

In certain embodiments, the present invention is directed to a sublingual spray formulation comprising:

-   -   an effective amount of buprenorphine, a pharmaceutically         acceptable salt thereof, or a derivative thereof;     -   water as a solvent;     -   a cosolvent selected from the group consisting of ethanol,         propylene glycol, and a mixture thereof;     -   an antioxidant selected from the group consisting of BHA, BHT,         methionine, sodium ascorbate, sodium thiosulfate, thioglycerol,         cysteine hydrochloride monohydrate and a mixture thereof; and     -   citric acid as a pH adjustor selected from the group consisting         of citric acid, sodium hydroxide and a mixture thereof.

In certain embodiments, the present invention is directed to a sublingual spray formulation comprising:

-   -   an effective amount of buprenorphine, a pharmaceutically         acceptable salt thereof, or a derivative thereof;     -   water as a solvent;     -   a solubilizer selected from the group consisting of         cyclodextrins such as hydroxpropyl beta-cyclodextrin (“HPβCD”),         sulfobutylether cyclodextrin, and a mixture thereof; and     -   an antioxidant selected from the group consisting of BHA, BHT,         methionine, sodium ascorbate, sodium thiosulfate, thioglycerol,         cysteine hydrochloride monohydrate and a mixture thereof.

In preferred embodiments, the present invention is directed to a sublingual spray formulation comprising:

-   -   an amount of buprenorphine from about 0.05% to about 10% w/w;     -   an amount of water from about 10% to about 95% w/w;     -   an amount of cosolvent from about 5% to about 90% w/w; and     -   an amount of antioxidant from about 0.0001% to about 0.5% w/w;         and     -   optionally, menthol as a permeation enhancer

In a more preferred embodiment, the present invention is directed to a sublingual spray formulation comprising:

-   -   an amount of buprenorphine from about 0.08% to about 1.3% w/w;     -   an amount of water from about 38% to about 40% w/w;     -   a cosolvent consisting of a mixture of ethanol in an amount of         55% w/w and propylene glycol in an amount of about 5% w/w;     -   an antioxidant consisting of a mixture of butylated         hydroxyanisole (BHA) in an amount of about 0.01% w/w and         butylated hydroxytoluene (BHT) in an amount of about 0.005% w/w;         and     -   menthol in an amount of about 0.05% w/w.

In preferred embodiments, the present invention is directed to a sublingual spray formulation comprising:

-   -   buprenorphine, a pharmaceutically acceptable salt thereof or a         derivative thereof at an amount from about 0.05% to about 10%         w/w;     -   naloxone, a pharmaceutically acceptable salt thereof or a         derivative thereof at an amount from about 0.005% to about 3%         w/w;     -   water as a solvent in an amount from about 10% w/w to about 95%         w/w;     -   a cosolvent consisting of a mixture of an alcohol and a glycol         in an amount from about 5% to about 90% w/w;     -   an antioxidant in an amount from about 0.001% to about 0.2% w/w;         and     -   a chelating agent in an amount from about 0.001% to about 0.1%         w/w.

In preferred embodiments, the present invention is directed to a sublingual spray formulation comprising:

-   -   buprenorphine, a pharmaceutically acceptable salt thereof or a         derivative thereof at an amount from about 0.05% to about 10%         w/w;     -   naloxone, a pharmaceutically acceptable salt thereof or a         derivative thereof at an amount from about 0.005% to about 3%         w/w;     -   water as a solvent in an amount from about 10% w/w to about 95%         w/w;     -   a cosolvent consisting of a mixture of an alcohol and a glycol         in an amount from about 5% to about 90% w/w;     -   an antioxidant in an amount from about 0.001% to about 0.2% w/w;     -   a chelating agent in an amount from about 0.001% to about 0.1%         w/w; and     -   menthol as a permeation enhancer.

In certain preferred embodiments the present invention is directed to a sublingual spray formulation comprising:

-   -   buprenorphine, a pharmaceutically acceptable salt thereof or a         derivative thereof at an amount from about 1.4% to about 8.6%         w/w;     -   naloxone, a pharmaceutically acceptable salt thereof or a         derivative thereof at an amount from about 0.4% to about 2.4%         w/w;     -   water as a solvent in an amount from about 28% w/w to 38% w/w;     -   a cosolvent consisting of a mixture of ethanol in an amount from         about 55% w/w and propylene glycol in an amount of about 5% w/w;     -   an antioxidant selected from a group consisting of butylated         hydroxyanisole, butylated hydroxytoluene, methionine, sodium         ascorbate, sodium thiosulfate, thioglycerol, cysteine         Hydrochloride monohydrate, and a mixture thereof in an amount         from about 0.001% to about 0.2% w/w, preferably sodium ascorbate         in an amount of about 0.02% w/w;     -   disodium edetate in an amount of about 0.005% w/w; and     -   menthol in an amount of about 0.05% w/w.

In certain preferred embodiments the present invention is directed to a sublingual spray formulation comprising:

-   -   buprenorphine, a pharmaceutically acceptable salt thereof or a         derivative thereof at an amount from about 0.05% to about 9.5%         w/w;     -   naloxone, a pharmaceutically acceptable salt thereof or a         derivative thereof at an amount from about 0.4% to about 2.7%         w/w;     -   water as a solvent in an amount from about 27.4% w/w to 39.7%         w/w;     -   a cosolvent consisting of a mixture of ethanol in an amount from         about 55% w/w and propylene glycol in an amount from about 5%         w/w; and     -   an antioxidant selected from a group consisting of butylated         hydroxyanisole, butylated hydroxytoluene, methionine, sodium         ascorbate, sodium thiosulfate, thioglycerol, cysteine         Hydrochloride monohydrate and a mixture thereof in an amount         from about 0.001% to about 0.2% w/w.

In certain preferred embodiments the present invention is directed to a sublingual spray formulation comprising:

-   -   buprenorphine, a pharmaceutically acceptable salt thereof or a         derivative thereof at an amount from about 0.05% to about 9.5%         w/w;     -   naloxone, a pharmaceutically acceptable salt thereof or a         derivative thereof at an amount from about 0.005% to about 2.7%         w/w;     -   water as a solvent in an amount from about 27.4% w/w to 39.7%         w/w;     -   a cosolvent consisting of a mixture of ethanol in an amount of         about 55% w/w and propylene glycol in an amount of about 5% w/w;         and     -   an antioxidant selected from a group consisting of butylated         hydroxyanisole, butylated hydroxytoluene, methionine, sodium         ascorbate, sodium thiosulfate, thioglycerol, cysteine         Hydrochloride monohydrate, and a mixture thereof in an amount         from about 0.001% to about 0.2% w/w.

In certain preferred embodiments the present invention is directed to a sublingual spray formulation comprising:

-   -   buprenorphine, a pharmaceutically acceptable salt thereof or a         derivative thereof at an amount from about 0.05% to about 9.5%         w/w;     -   naloxone, a pharmaceutically acceptable salt thereof or a         derivative thereof at an amount from about 0.005% to about 3%         w/w;     -   water as a solvent in an amount from about 27.4% w/w to 39.7%         w/w;     -   a cosolvent consisting of a mixture of ethanol in an amount of         about 55% w/w and propylene glycol in an amount of about 5% w/w;     -   an antioxidant selected from a group consisting of butylated         hydroxyanisole, butylated hydroxytoluene, methionine, sodium         ascorbate, sodium thiosulfate, thioglycerol, cysteine         Hydrochloride monohydrate, and a mixture thereof; and     -   ethylenediaminetetraacetic acid disodium (disodium edetate) as a         chelating agent in an amount of about 0.005% w/w or citric acid         as a pH adjustor in an amount from about 0.0025 to 10% w/w.

In certain embodiments, the sublingual spray formulations of the present invention contain naloxone in an amount that discourages improper administration of the formulations. When the naloxone containing formulations are properly administered, the naloxone is delivered at a rate that is below that which would be therapeutic. In this context, “therapeutic” refers to an amount of naloxone that would block the effects of the buprenorphine that is concurrently administered in the sublingual spray formulation. If the formulations are improperly used, however, the naloxone in the formulation could be sufficient to block the effects of buprenorphine.

In certain embodiments, the present invention is directed to methods for treating pain comprising administering a sublingual spray formulation of the present invention to a patient.

In certain embodiments, the present invention is directed to methods for treating opioid dependence comprising administering a sublingual spray formulation of the present invention to a patient.

In an embodiment, the present invention is directed to sublingual spray formulations wherein the C_(max) (ng/mL) of buprenorphine is from about 0.6 to about 0.8. In a preferred embodiment, the C_(max) (ng/mL) of buprenorphine is 0.76 following sublingual administration.

In yet another embodiment, the present invention is directed to sublingual spray formulations wherein the T_(max) of buprenorphine is from about 1.5 to about 1.9 hours. In a preferred embodiment, the T_(max) of buprenorphine is about 1.75 hours following sublingual administration.

In yet another embodiment, the present invention is directed to sublingual spray formulations wherein the C_(max) (ng/mL) of buprenorphine is from about 1.2 to about 1.5. In a preferred embodiment, the C_(max) (ng/mL) of buprenorphine is about 1.38 following sublingual administration.

In a further embodiment, the present invention is directed to sublingual spray formulations wherein the T_(max) of buprenorphine is from about 1.2 to about 1.7 hours. In a preferred embodiment, the T_(max) of buprenorphine is about 1.5 hours following sublingual administration.

In another embodiment, the present invention is directed to sublingual spray formulations wherein greater than 98% of the formulation particles are greater than 10 microns in diameter during administration.

In another embodiment, the present invention is directed to sublingual spray formulations wherein the mean Dv(10) is from about 10 to about 30 microns during administration.

In another embodiment, the present invention is directed to sublingual spray formulations wherein the mean Dv(50) is from about 30 to about 80 microns during administration.

In another embodiment, the present invention is directed to sublingual spray formulations wherein the mean Dv(90) is from about 80 to about 200 microns during administration.

In a further embodiment, the present invention is directed to sublingual spray formulations that when administered provide a spray plume ovality ratio of from about 1.1 to 2.4.

In yet another embodiment, the invention is directed to sublingual formulations that when administered provide a plume width of from about 25 to about 45 millimeters.

In a further embodiment, the invention is directed to sublingual formulations that when administered provide a plume angle of from about 30 to about 55 degrees.

In yet another embodiment, the invention is directed to sublingual formulations that when administered provide a D(4,3) of 55 to 95 microns.

In an additional embodiment, the invention is directed to sublingual formulations that when administered provide a spray span ((Dv90−Dv10)/Dv50) of from about 1.2 to about 3.3.

BRIEF DESCRIPTION OF THE DRAWINGS

The patent or application file contains at least one drawing executed in color. Copies of this patent or patent application publication with color drawing(s) will be provided by the Office upon request and payment of the necessary fee.

FIG. 1 depicts a flow chart describing the disposition of the study of the effect of buprenorphine sublingual spray to treat bunionectomy-related pain.

FIG. 2 depicts a chart of a chart of Numeric Rating Scale (NRS) Summed Pain Intensity Difference (SPID) at 4, 8, 24 and 48 hours.

FIG. 3 depicts a chart of time of onset of analgesia for placebo, 0.5 mg tid, 0.25 mg tid and 0.125 tid doses.

DETAILED DESCRIPTION OF THE INVENTION

The present invention is directed to a sublingual spray formulation comprising an effective amount of buprenorphine or buprenorphine and naloxone, pharmaceutically acceptable salts thereof, or derivatives thereof. The present invention further relates to a method of treating pain or opioid dependence by administering an effective amount of a sublingual spray formulation of the present invention to a patient in need thereof.

The present invention is further directed to a sublingual spray formulation comprising an effective amount of buprenorphine or buprenorphine and naloxone, pharmaceutically acceptable salts thereof, or derivatives thereof, a solvent, a cosolvent and an antioxidant.

Applicants developed new sublingual buprenorphine and buprenorphine/naloxone formulations that unexpectedly are storage stable, safe and effective. Specifically, Applicants were surprised that the formulations were stable at high temperatures (40 degrees Celsius) for an extended period of time (see Examples 1 and 2 below). Further, Applicants unexpectedly found that the formulations provided a quick onset of action and bioavailability (as demonstrated by pharmacokinetic studies, see Example 3 below). The formulations upon administration exhibit excellent droplet size distribution, as well.

As used herein the term “patient” refers but is not limited to a person that is being treated for pain, opioid dependence or another affliction or disease that can be treated with buprenorphine.

As used herein the term “pharmaceutically acceptable” refers to ingredients that are not biologically or otherwise undesirable in a sublingual dosage form.

As used herein the term “effective amount” refers to the amount necessary to treat a patient in need thereof.

Pharmaceutically acceptable salts that can be used in accordance with the current invention include but are not limited to hydrochloride, hydrobromide, hydroiodide, nitrate, sulfate, bisulfate, phosphate, acid phosphate, isonicotinate, acetate, lactate, salicylate, citrate, tartrate, pantothenate, bitartrate, ascorbate, succinate, maleate, gentisinate, fumarate, gluconate, glucaronate, saccharate, formate, benzoate, glutamate, methanesulfonate, ethanesulfonate, benzensulfonate, p-toluenesulfonate and pamoate (i.e., 1,1′-methylene-bis-(2-hydroxy-3-naphthoate)) salts.

In preferred embodiments the pharmaceutically acceptable salt is hydrochloride.

Derivatives of buprenorphine that can be used in accordance with the current invention include but are not limited norbuprenorphine, thenorphine, demethoxybuprenorphine and esters and diastereomers of buprenorphine.

The solvent used with the present invention is United States Pharmacopeia (“USP”) purified water.

Cosolvents that can be used in accordance with the current invention are alcohols, and glycols or a mixture thereof.

Alcohols that can be used in accordance with the current invention include but are not limited to methanol, ethanol, propyl alcohol, and butyl alcohol.

Glycols that can be used in accordance with the current invention include but are not limited to propylene glycol, butylene glycol and polyethylene glycols such as PEG 200 and PEG 400 and the like.

In preferred embodiments the cosolvent is ethanol or propylene glycol or a mixture thereof.

In more preferred embodiments the amount of cosolvent included in the formulation is from about 5% to about 90% w/w.

In other more preferred embodiments the amount of cosolvent included in the formulation is from about 2 to about 10% propylene glycol. In a most preferred embodiment the amount of cosolvent is about 5% w/w propylene glycol.

In other more preferred embodiments the amount of cosolvent included in the formulation is about 40% w/w to about 60% w/w ethanol. In a most preferred embodiment the amount of cosolvent is about 55% w/w ethanol.

In other more preferred embodiments the cosolvent is a mixture of propylene glycol at about 5% w/w and ethanol at about 55% w/w.

Solubilizers that can be used in accordance with the current invention are hydroxpropyl beta-cyclodextrin (“HPβCD”) and sulfobutylether cyclodextrin or a mixture thereof.

In preferred embodiments the solubilizer is HPβCD.

In more preferred embodiments the amount of HPβCD is from about 10% w/w to 40% w/w. In a most preferred embodiment the amount of HPβCD is about 30% w/w.

Antioxidants that can be used in accordance with the current invention include but are not limited to butylated hydroxyanisole (“BHA”), butylated hydroxytoluene (“BHT”), methionine, sodium ascorbate, sodium thiosulfate and thioglycerol, cysteine Hydrochloride monohydrate or a mixture thereof.

In preferred embodiments the amount of antioxidant included in the formulation is from about 0.001% to about 0.05% w/w.

In more preferred embodiments the amount of antioxidant is about 0.01% w/w of BHA.

In other more preferred embodiments the antioxidant is a mixture of about 0.01% w/w of BHA and about 0.005% w/w of BHT.

In other more preferred embodiments the antioxidant is about 0.01% w/w of sodium thiosulfate.

In other more preferred embodiments the antioxidant is about 0.02% w/w of sodium ascorbate.

Permeation enhancers that can be used in accordance with the current invention include but are not limited to menthol, Tween® 80 (Tween is a registered trademark of Uniqema Americas, LLC), sodium lauryl sulfate, glyceryl oleate, oleic acid, cetylpyridium chloride, and sodium desoxy cholate.

In preferred embodiments the amount of permeation enhancer is from about 0.001% to about 0.1% w/w.

In more preferred embodiments the amount of permeation enhancer is about 0.05% w/w of menthol.

Chelating agents that can be used in accordance with the present invention include but are not limited to ethylenediaminetetraacetic acid disodium (“disodium edetate” or edetate disodium dihyrdate”).

In preferred embodiments the amount of disodium edetate is about 0.005% to about 0.01% w/w.

Formulations of the present invention may have a pH range from about 3.0 to about 7.0, preferably from about 3.5 to about 5.5 and more preferably from about 3.8 to about 5.1. pH adjustors that can be used in accordance with the present invention include but are not limited to citric acid, sodium hydroxide and a mixture thereof. In preferred embodiments the amount of citric acid is from about 2% to about 20% w/w. In more preferred embodiments the amount of citric acid is about 15%. In other more preferred embodiments the amount of citric acid is about 10%.

As used herein, all numerical values relating to amounts, weights, and the like, that are defined as “about” each particular value is plus or minus 10%. For example, the phrase “about 10% w/w” is to be understood as “9% to 11% w/w.” Therefore, amounts within 10% of the claimed value are encompassed by the scope of the claims.

As used herein “% w/w” refers to the percent weight of the total formulation.

Representative Embodiments

In a more preferred embodiment the sublingual spray formulation comprises:

-   -   an amount of buprenorphine of about 0.54% w/w;     -   an amount of water of about 39.4% w/w;     -   a cosolvent as a mixture of ethanol in an amount of about 55%         w/w and propylene glycol in an amount of about 5% w/w;     -   an antioxidant as a mixture of BHA in an amount of about 0.01%         w/w and BHT in an amount of about 0.005% w/w; and     -   menthol as a permeation enhancer in an amount of about 0.05%         w/w.

In another more preferred embodiment the sublingual spray formulation comprises:

-   -   an amount of buprenorphine of about 0.54% w/w;     -   an amount of water of about 39.4% w/w;     -   a cosolvent as a mixture of ethanol in an amount of about 55%         w/w and propylene glycol in an amount of about 5% w/w;     -   sodium thiosulfate as an antioxidant in an amount of about 0.01%         w/w;     -   menthol as a permeation enhancer in an amount of about 0.05%         w/w; and     -   citric acid as a pH adjustor in an amount of about 0.002% w/w.

In another more preferred embodiment the sublingual spray formulation comprises:

-   -   an amount of buprenorphine of about 0.54% w/w;     -   an amount of water of about 39.39% w/w;     -   a cosolvent as a mixture of ethanol in an amount of about 55%         w/w and propylene glycol in an amount of about 5% w/w;     -   sodium ascorbate as an antioxidant in an amount of about 0.01%         w/w;     -   menthol as a permeation enhancer in an amount of about 0.05%         w/w; and     -   disodium edetate as a chelating agent in an amount of about         0.01% w/w.

In a most preferred embodiment the sublingual spray formulation comprises:

-   -   an amount of buprenorphine of about 0.54% w/w;     -   an amount of water of about 39.45% w/w;     -   a cosolvent as a mixture of ethanol in an amount of about 55%         w/w and propylene glycol in an amount of about 5% w/w; and     -   BHA as an antioxidant in an amount of about 0.01% w/w.

In a more preferred embodiment the sublingual spray formulation comprises:

-   -   an amount of buprenorphine of about 8.602% w/w;     -   an amount of naloxone of about 2.44% w/w;     -   an amount of water of about 29% w/w;     -   an amount of sodium thiosulfate of about 0.01% w/w; and     -   an amount of citric acid of about 0.0025% w/w.

In a more preferred embodiment the sublingual spray formulation comprises:

-   -   an amount of buprenorphine of about 8.602% w/w;     -   an amount of naloxone of about 2.44% w/w;     -   an amount of water of about 29% w/w;     -   an amount of sodium thiosulfate of about 0.01% w/w; and     -   an amount of disodium edetate of about 0.005% w/w.

In a more preferred embodiment the sublingual spray formulation comprises:

-   -   an amount of buprenorphine of about 8.602% w/w;     -   an amount of naloxone of about 2.44% w/w;     -   an amount of water of about 29% w/w;     -   an antioxidant as a mixture of BHA in an amount of about 0.01%         w/w and BHT in an amount of about 0.005% w/w; and     -   an amount of disodium edetate of about 0.005% w/w.

In a more preferred embodiment the sublingual spray formulation comprises:

-   -   an amount of buprenorphine of about 8.602% w/w;     -   an amount of naloxone of about 2.44% w/w;     -   an amount of water of about 29% w/w;     -   an amount of sodium ascorbate of about 0.02% w/w; and     -   an amount of disodium edetate of about 0.005% w/w.

In a more preferred embodiment the sublingual spray formulation comprises:

-   -   an amount of buprenorphine of about 8.39% w/w;     -   an amount of naloxone of about 2.37% w/w;     -   an amount of water of about 29% w/w;     -   an amount of ethanol of about 55% w/w;     -   an amount of propylene glycol of about 5% w/w;     -   an amount of sodium ascorbate of about 0.02% w/w;     -   an amount of disodium edetate of about 0.005% w/w; and     -   an amount of menthol of about 0.05% w/w.

In a more preferred embodiment the sublingual spray formulation comprises:

-   -   an amount of buprenorphine of about 5.554% w/w;     -   an amount of naloxone of about 1.57% w/w;     -   an amount of water of about 33% w/w;     -   an amount of ethanol of about 55% w/w;     -   an amount of propylene glycol of about 5% w/w;     -   an amount of sodium ascorbate of about 0.02% w/w;     -   an amount of disodium edetate of about 0.005% w/w; and     -   an amount of menthol of about 0.05% w/w.

In a more preferred embodiment the sublingual spray formulation comprises:

-   -   an amount of buprenorphine of about 2.84% w/w;     -   an amount of naloxone of about 0.804% w/w;     -   an amount of water of about 36% w/w;     -   an amount of ethanol of about 55% w/w;     -   an amount of propylene glycol of about 5% w/w;     -   an amount of sodium ascorbate of about 0.02% w/w;     -   an amount of disodium edetate of about 0.005% w/w; and     -   an amount of menthol of about 0.05% w/w.

In a more preferred embodiment the sublingual spray formulation comprises:

-   -   an amount of buprenorphine of about 1.42% w/w;     -   an amount of naloxone of about 0.402% w/w;     -   an amount of water of about 38% w/w;     -   an amount of ethanol of about 55% w/w;     -   an amount of propylene glycol of about 5% w/w;     -   an amount of sodium ascorbate of about 0.02% w/w;     -   an amount of disodium edetate of about 0.005% w/w; and     -   an amount of menthol of about 0.05% w/w.

In another more preferred embodiment the sublingual spray formulation comprises:

-   -   an amount of buprenorphine from about 0.813% to about 1.3% w/w,         preferably 0.0813% w/w, 0.1625% w/w, 0.325% w/w, 0.65% w/w or         1.3% w/w;     -   an amount of BHA of about 0.01% w/w;     -   an amount of BHT of about 0.005% w/w;     -   an amount of ethanol of about 55% w/w;     -   an amount of propylene glycol of about 5% w/w; and     -   an amount of water from about 39.8537% to about 38.635% w/w,         preferably 39.8537% w/w, 39.7725% w/w, 39.61% w/w, 39.285% w/w         or 38.635% w/w.

The following examples are intended to illustrate the present invention and to teach one of ordinary skill in the art how to make and use the invention. They are not intended to be limiting in any way.

EXAMPLES Example 1: Stable Buprenorphine Formulations

Method of Making the Formulations

Sublingual spray formulations were created by first degassing ethanol and USP purified water, separately. Next, the ethanol and purified water were each purged with nitrogen. Soluble excipients were then dissolved in either the ethanol or the purified water based on their solubility. Next, the solutions were combined. Active pharmaceutical ingredient/s was/were added to the final solution and mixed until dissolved.

Formulations

TABLE 1 Stable Sublingual Buprenorphine Spray Formulations Formulation Control #1 #2 #3 #4 #5 #6 #7 #8 #9 Buprenorphine HCl 0.538 0.538 0.538 00538 0.538 0.538 0.538 0.538 0.538 0.538 Water (USP) 39.462 39.452 39.397 39.372 89.427 94.427 39.39 39.4 39.405 69.472 Ethanol 55 55 55 55 10 55 55 55 Propylene Glycol 5 5 5 5 5 5 5 5 HPβCD 30 BHA 0.01 0.01 BHT 0.005 Sodium Ascorbate 0.02 0.02 0.02 0.01 0.02 Sodium Thiosulfate 0.01 Methionine 0.005 Menthol 0.05 0.05 0.05 0.05 0.05 Citric Acid 0.02 0.015 0.015 0.002 0.002 Disodium Edetate 0.01 pH 5.09 4.99 5.11 4.71 4.01 4 4.43 3.9 3.85 No Data values = % w/w

Stability Data

The formulations listed in Table 1 were subject to stability test at 40° C.±20° C. under 75%±5% relative humidity for six months. Stability data was collected at zero, and six months. Assay and impurities were detected using high performance liquid chromatography with an ultraviolet detector. The assay was performed at 288 nm and indicated as a % of initial concentration. For all impurities, analysis was performed at 240 nm and expressed as a % area. Amounts of particular impurities are listed in Table 2 as a percentage of the area of each formulation along with amount of total impurities.

TABLE 2 Stability Data for Sublingual Buprenorphine Spray Formulations stored at 40° C. ± 2° C. under 75% ± 5% relative humidity, Control #1 #2 #3 #4 Time (m) 0 6 0 6 0 6 0 6 0 6 Assay 100 104 100 104.2 100 104.1 100 103.3 100 102.7 A BQL ND BQL ND ND ND BQL ND ND ND B ND 0.27 ND 0.09 ND 0.06 ND 0.21 ND 0.05 D ND BQL ND ND ND ND ND ND ND ND G BQL 0.64 ND 0.06 ND BQL ND 0.11 0.11 0.68 H ND ND ND ND ND ND ND ND ND ND Bisalkyl- ND ND ND 0.31 ND BQL ND ND ND ND buprenorphine UnSpecified BQL ND ND ND ND ND ND ND ND ND Total 0 0.91 0 0.46 0 0.06 0 0.32 0.11 0.73 (% area) #5 #6 #7 #8 #9 Time (m) 0 6 0 6 0 6 0 6 0 6 Assay 100 99.2 100 99.3 100 99.6 100 98.2 100 101.8 A ND ND ND 0.06 ND BQL ND 0.05 ND ND B ND 0.09 ND 0.17 ND 0.08 ND 0.2 ND BQL D ND ND ND ND ND ND ND ND ND ND G 0.09 0.77 ND 0.07 ND ND ND 0.34 ND 0.4 H ND ND ND 0.08 ND ND ND ND ND BQL Bisalkyl- ND ND ND 0.05 ND ND ND ND ND ND buprenorphine UnSpecified ND 0.06 BQL ND 0.05 0.08 0.06 0.21 ND ND Total 0.09 0.92 0 0.43 0.05 0.16 0.06 0.8 0 0.4 (% area) BQL = Below Quantifiable Limit; ND = Not Detected

Sublingual buprenorphine spray formulations contained less than one percent total impurities after six months at 40° C. Control and formulations 1, 3, 4, 5, 6, 8 and 9 showed significant increase in levels of individual impurities (impurity B, impurity G, bisalkyl or unspecified impurity) at the 6 month time point whereas formulations containing BHA and BHT (#2) or sodium thiosulfate (#7) showed good stability. pH also played a role in the stability of the product. These results represent sublingual buprenorphine spray formulations that would remain stable for two years at room temperature.

Example 2: Stable Buprenorphine/Naloxone Formulations

Method of Making the Formulations

Sublingual spray formulations were created by first degassing ethanol and USP purified water, separately. Next, the ethanol and purified water were each purged with nitrogen. Soluble excipients were then dissolved in either the ethanol or the purified water based on their solubility. Next, the solutions were combined. Buprenorphine and naloxone were added to the final solution and mixed until dissolved.

Formulations

TABLE 3 Stable Buprenorphine/Naloxone Sublingual Spray Formulations Formulation Control #2 #10 #11 #12 #13 Buprenorphine HCl 8.602 8.602 8.602 8.602 8.602 Naloxone HCl 2.44 2.44 2.44 2.44 2.44 Water (USP) 28.958 28.9455 28.943 28.938 28.933 Ethanol 55 55 55 55 55 Propylene Glycol 5 5 5 5 5 BHA 0.01 BHT 0.005 Sodium Ascorbate 0.02 Sodium Thiosulfate 0.01 0.01 Citric Acid 0.0025 Disodium Edetate 0.005 0.005 0.005 values = % w/w Stability Data

The formulations listed in Table 3 were subject to stability test at 40° C.±2° C. under 75%±5% relative humidity three months and at ±25° C. under 60%±5% relative humidity for three months. Stability data was collected at zero, one, two and three months at 40° C. and at zero, one and three months at 25° C. Assay and impurities were detected using high performance liquid chromatography with an ultraviolet detector. Buprenorphine assay was performed at 288 nm and indicated as a % of initial concentration. For all buprenorphine impurities, analysis was performed at 240 nm and expressed as a % area. Naloxone assay was performed at 280 nm and indicated as a % of initial concentration and for all naloxone impurities, analysis was performed at 230 nm. Amounts of particular impurities are listed in Tables 4 and 5 for 40° C. and in Table 6 for 25° C. as a percentage of the area of each formulation along with amount of total impurities. Relative retention time (“RRT”) is given for each impurity.

TABLE 4 Stability Data for Control #2 stored at 40° C. ± 2° C./75% ± 5% relative humidity for 1, 2 and 3 months. 40° C. Control #2 40° C. Control #2 Buprenorphine RRT 0 m 1 m 2 m 3 m Naloxone RRT 0 m 1 m 2 m 3 m Assay  100% 96.93%  94.22%  94.27%  Assay  100% 96.31%  97.22%  95.62%  Impurity B 0.4 ND ND 0.09% 0.12% Impurity C 0.66 ND 1.11% 1.71% 2.02% Impurity J 1.1 ND ND BQL BQL Impurity A 0.83 ND ND 0.10% 0.19% Impurity F 1.27 ND ND BQL BQL Impurity E 2.85 ND ND 0.09% ND Impurity G 1.8 0.11% 1.84% 3.10% 4.14% Impurity D 0.20 ND ND ND 0.09% Unknown 0.26 ND ND ND BQL Unknown 0.28 ND 0.09% 0.17% 0.23% Impurities 0.86 ND 0.28% 0.46% 0.63% Impurities 0.30 ND ND 0.09% 0.17% 2.15 ND 0.23% 0.33% 0.42% 0.47 ND ND ND 0.06% Total (% area) 0.11% 2.35% 3.98% 5.31% 0.52 ND 0.34% 0.73% 1.17% 4.30 ND ND ND 0.33% Total (% area) 0.00% 1.54% 2.89% 4.26% BQL = Below Qantifiable Limit; ND = Not Detected

The control formulation for the buprenorphine/naloxone sublingual spray formulation contained greater than 1% impurities of both buprenorphine and naloxone within one month at 40° C. and between about 4% and about 5% at three months.

TABLE 5 Stability Data for Buprenorphine/Naloxone Sublingual Spray Formulations stored at 40° C. ± 2° C./75% ± 5% relative humidity for 1, 2 and 3 months. 40° C. #10 #11 Buprenorphine RRT 0 m 1 m 2 m 3 m RRT 0 m 1 m 2 m 3 m Assay  100% 98.72% 96.90%  100.06%   100% 99.26%  98.91%  99.96%  Impurity G Total (% area) 0.00%  0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% Naloxone RRT 0 m 1 m 2 m 3 m RRT 0 m 1 m 2 m 3 m Assay  100% 99.19% 102.69%  102.42%   100% 99.84%  102.75%  102.00%  Impurity C Unknown Impurities Total (% area) 0.00%  0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 40° C. #12 #13 Buprenorphine RRT 0 m 1 m 2 m 3 m RRT 0 m 1 m 2 m 3 m Assay 100   99.50% 101.44%  101.22%   100% 99.06%  100.30%  99.36%  Impurity G 1.8 ND ND ND 0.05% Total (% area) 0.00%  0.00% 0.00% 0.05% 0.00% 0.00% 0.00% 0.00% Naloxone RRT 0 m 1 m 2 m 3 m RRT 0 m 1 m 2 m 3 m Assay  100% 97.91% 102.36%  103.11%   100% 101.42%  102.72%  103.38%  Impurity C 0.66 ND ND 0.11% 0.14% 0.66 ND ND ND 0.09% Unknown 0.52 ND ND 0.07% 0.12% 0.52 ND ND BQL ND Impurities 4.02 ND ND ND ND Total (% area) 0.00%  0.00% 0.18% 0.26% 0.00% 0.00% 0.00% 0.09% BQL = Below Qantifiable Limit; ND = Not Detected

All formulations had less than 1% total impurities at three months. Similar to the buprenorphine only formulations in Example 1, formulations containing sodium thiosulfate (#10 and #11) were exceptionally stable with no impurities after three months. Formulation #12 contains BHA and BHT as the antioxidant and had significant impurities of naloxone (0.26% total impurities). Formulation #13 contains sodium ascorbate and had no impurities of buprenorphine and 0.09% total impurities of naloxone. These results represent sublingual spray formulations that would remain stable for one year at room temperature.

TABLE 6 Stability Data for Buprenorphine/Naloxone Sublingual Spray Formulations stored at 25° C. ± 2° C./60% ± 5% relative humidity for 1, 2 and 3 months. 25° C. Control #2 #10 #11 Buprenorphine RRT 0 m 1 m 3 m RRT 0 m 1 m 3 m RRT 0 m 1 m 3 m Assay  100% 97.33%  98.25%   100% 100.14%  98.82%   100% 100.01%  99.80%  Impurity G 1.8 0.11% 0.44% 1.08% Unknown 0.86 ND ND 0.13% Impurities 1.8 ND ND 0.09% Total (% area) 0.11% 0.44% 1.30% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% Naloxone RRT 0 m 1 m 3 m RRT 0 m 1 m 3 m RRT 0 m 1 m 3 m Assay  100% 98.56%  100.00%   100% 99.08%  101.67%   100% 99.03%  102.16%  Impurity C 0.66 ND 0.41% 0.97% Impurity A Unknown 0.28 ND ND 0.08% Impurites 0.52 ND ND 0.13% Total (% area) 0.00% 0.41% 1.18% 0.93% 0.00% 0.00% 0.00% 0.00% 0.00% 25° C. #12 #13 Buprenorphine RRT 0 m 1 m 3 m RRT 0 m 1 m 3 m Assay 100      101.29%  100.14%  100% 98.37%  99.74%  Impurity G Unknown Impurities Total (% area) 0.00% 0.00%  0.00% 0.00% 0.00% 0.00% Naloxone RRT 0 m 1 m 3 m RRT 0 m 1 m 3 m Assay 100% 99.03%  101.77%  100% 100.65%  102.67%  Impurity C Impurity A 0.83 ND ND 0.11% Unknown 0.52 ND ND BQL Impurities Total (% area) 0.00% 0.00%  0.00% 0.00% 0.00% 0.11% BQL = Below Qantifiable Limit; ND = Not Detected

The control formulation had greater than 1% impurities at three months. All formulations containing antioxidants had less than 1% total impurities at three months. Similar to the buprenorphine only formulations in Example 1, formulations containing sodium thiosulfate (#10 and #11) or a mixture of BHA and BHT (#12) were exceptionally stable with no impurities after three months. Formulation #13 which contains sodium ascorbate had no impurities of buprenorphine and 0.11% total impurities of naloxone after storage at 25° C.±2° C./75%±5% relative humidity.

Example 3: Pharmacokinetics of Buprenorphine Sublingual Spray Formulations

A study was designed and executed to determine the pharmacokinetics of buprenorphine sublingual spray formulations of the present invention after administration in healthy volunteers under fasting conditions.

The study was a single center, single dose, open-label, 1-sequence, 2-period, ascending dose study design in twelve healthy male and female subjects. The following dose levels of the investigational product were administered under fasting conditions: Dose 1: A single 0.5 mg dose (1 spray of 100 microliters) of Buprenorphine 5 mg/mL Sublingual Spray; and Dose 2: A single 1.0 mg dose (2 sprays of 100 microliters) of Buprenorphine 5 mg/mL Sublingual Spray.

The subjects arrived at the clinical site more than 10 hours before the buprenorphine administration. The subjected were supervised overnight (while fasting) and a single 50 mg dose of naltrexone (1×50 mg tablet) was orally administered with 240 mL of water approximately 1 hour prior to the buprenorphine administration to provide blockade of the pharmacological effects of buprenorphine. Then, a single dose (0.5 mg in period 1 and 1.0 mg in period 2) of the buprenorphine formulation was sublingually administered in the morning. Subjects were allowed to leave the clinical site after the 24-hour post-dose blood draw and returned to the clinical site before the remaining blood sample. The second dose level was administered following favorable safety review. The buprenorphine administrations were separated by a wash-out of 14 calendar days. The parameters are summarized below in Table 7.

TABLE 7 Summary of Pharmacokinetic Parameters Buprenorphine Buprenorphine 0.5 mg 1 mg Parameter MEAN C.V. MEAN C.V. C_(max) (ng/mL) 0.761 19.0 1.38 10.2 In(C_(max)) −0.2904 −67.1 0.3169 31.2 T_(max) (hours)* 1.75 30.8 1.50 30.6 AUC_(0-T) (ng · h/mL) 4.37 13.6 9.12 10.7 In(AUC_(0-T)) 1.4671 9.0 2.2053 5.0 AUC_(0-∞) (ng · h/mL) 4.81 13.3 10.2 10.6 In(AUC_(0-∞)) 1.5614 8.7 2.3170 4.7 AUC_(0-T/∞) (%) 91.19 6.6 89.49 3.5 λ_(Z) (hours⁻¹) 0.0959 53.3 0.0313 17.0 T_(half) (hours) 9.75 57.4 22.87 20.1 V_(D)/F (L) 1450 54.9 3250 19.4 Cl/F (L/h) 106 13.8 99.1 11.2 C_(max)/D (ng/mL) 0.761 19.0 0.690 10.2 In(C_(max)/D) −0.2904 −67.1 −0.3763 −26.3 AUC_(0-T)/D (ng · h/mL) 4.37 13.6 4.56 10.7 In(AUC_(0-T)/D) 1.4671 9.0 1.5122 7.3 AUC_(0-∞)/D (ng · h/mL) 4.81 13.3 5.10 10.6 In(AUC_(0-∞)/D) 1.5614 8.7 1.6238 6.7 *T_(max), the median is presented

As seen in Table 7, the C_(max) obtained for buprenorphine were 0.761 ng/mL and 1.38 ng/mL. The T_(max) observed for buprenorphine was 1.75 and 1.50 hours following the ascending doses.

Example 4: Bioavailability of Buprenorphine

A study was designed and executed in order to compare the rate and extent of absorption and bioavailability of 1 mg buprenorphine sublingual spray formulations of the present invention with 0.3 mg (1 mL) Buprenex® (buprenorphine HCl) intramuscular injection and 0.3 mg (1 mL) Buprenex® (buprenorphine HCl) intravenous bolus injection.

This was an open-label, 3-treatment, 3-period, 6-sequence, single-dose, randomized crossover study. Eighteen healthy male and female volunteers were randomly assigned to 1 of 6 treatment sequences. Dosing occurred after an overnight fast and there was a minimum 14-day washout between the dosing in two periods. Blood samples for the measurement of the plasma concentrations of buprenorphine were collected before (pre-dose) and at 5, 10, 20, 30, and 40 minutes and at 1, 1.25, 1.5, 2, 4, 6, 8, 10, 12, 16, 24, 36, 48, 72, 96, 120, and 144 hours after dosing. The results of this study are summarized below in Table 8.

TABLE 8 Bioavailability of Buprenorphine Sublingual Spray Intramuscular Intravenous Parameter* 1 mg 0.3 mg 0.3 mg Cmax (ng/mL) 1.20 ± 0.507 1.73 ± 1.08 3.95 ± 3.66 (18) (18) (18) Tmax (h) 1.50 0.17 0.083 (18) (18) (18) [0.50-2.00] [0.083-1.50] [0.083-0.333] AUC(0-t) 7.31 ± 2.80 4.97 ± 0.90 5.09 ± 1.01 (h × ng/mL) (18) (18) (18) AUC(inf) 8.19 ± 3.27 5.50 ± 0.83 5.51 ± 1.21 (h × ng/mL) (15) (15) (17) λz (1/h) 0.0551 ± 0.0357 0.0655 ± 0.0210 0.1028 ± 0.0641 (15) (15) (17) t½ (h) 17.1 ± 8.62 12.0 ± 5.31 9.37 ± 6.49 (15) (15) (17)

The absolute bioavailability of buprenorphine, based on AUC(0-t) and AUC(inf), after sublingual administration was 41.03% and 42.57%, respectively.

Example 5: Buprenorphine Spray Droplet Size Distribution Spray Pattern and Plume Geometry

A challenge of creating a buprenorphine sublingual spray formulation is that it must be capable of producing spray droplets that are over 10 microns in diameter. Spray droplets 10 microns or smaller could be inhaled into the lungs. The optimal particle size for sublingual spray droplets is from 20 to about 200 microns in diameter. It is desirable for the formulation to have droplet sizes near 20 because this increases the surface area and increased surface area exposure is one factor that contributes to a high bioavailability. Sublingual formulations should be able to maintain a consistent droplet size throughout its shelf life. Applicants found during testing that formulations of the present invention yielded desirable droplet sizes for sublingual administration. The testing also revealed that the formulation dose remains consistent when administered with a spray pump.

Five milligram per mL buprenorphine spray formulations of the present invention were subjected to two different storage conditions (25 and 40 degrees C.) and samples were taken at two different times (5M and 6M) for spray droplet size distribution analysis. Droplet analysis was conducted using standard laser analysis procedures known by those of skill in the art.

Droplet size distribution (Dv10, Dv50, Dv90, percent droplets less than 10 micrometers in diameter, D(4,3) and Span tested at two distances, 3 cm and 6 cm for upright and horizontal samples stored at 25 and 40 degrees C.) and spray pattern (Dmin, Dmax and ovality ratio tested at two distances, 3 cm and 6 cm for upright and horizontal samples stored at 25 and 40 degrees C.) were determined. D(4,3) refers to the volume moment mean of the particles; Dv10 refers to droplet size for which 10% of the total volume is obtained; Dv50 refers to droplet size for which 50% of the total volume is obtained; Dv90 refers to droplet size for which 90% of the total volume is obtained; Span refers to distribution span (Dv90−Dv10)/Dv50; DSD refers to droplet size distribution; the temperature listed is the storage temperature; U refers to an upright position of the spray pump; and H refers to horizontal position of the spray pump. The results of these studies can be seen below in Tables 9 to 40.

In addition, the formulations were tested for plume geometry including width and angle using standard procedures known by those of skill in the art. This testing showed that the spray pattern and plume were acceptable for formulations of the present invention. The results of these studies can be seen below in Tables 41 and 42.

TABLE 9 Droplet Size Distribution at 3 cm for sample stored at 25 degrees C., Upright position, 5M DSD 3 cm Dv(10) Dv(50) Dv(90) % D(4, 3) 25° C.-U (μm) (μm) (μm) <10μ (μm) Span Mean 25.37 53.25 111.1 0.9507 62.07 1.609 Range Min 24.38 51.44 106.0 0.8534 59.51 1.539 Max 26.20 55.85 119.4 1.0410 65.72 1.705

TABLE 10 Droplet Size Distribution at 6 cm for sample stored at 25 degrees C., Upright position, 5M DSD 6 cm Dv(10) Dv(50) Dv(90) % D(4, 3) 25° C.-U (μm) (μm) (μm) <10μ (μm) Span Mean 30.58 56.68 102.7 1.5794 62.37 1.270 Range Min 28.93 52.00 90.5 1.4610 56.45 1.171 Max 31.60 60.47 113.4 1.7840 67.41 1.355

TABLE 11 Droplet Size Distribution at 3 cm for sample stored at 25 degrees C., Horizontal position, 5M DSD 3 cm Dv(10) Dv(50) Dv(90) % D(4, 3) 25° C.-H (μm) (μm) (μm) <10μ (μm) Span Mean 24.65 53.78 138.2 0.7813 72.37 2.123 Range Min 21.87 50.76 105.8 0.0000 59.42 1.593 Max 26.70 58.10 194.5 1.1560 89.39 3.295

TABLE 12 Droplet Size Distribution at 6 cm for sample stored at 25 degrees C., Horizontal position, 5M DSD 6 cm Dv(10) Dv(50) Dv(90) % D(4, 3) 25° C.-H (μm) (μm) (μm) <10μ (μm) Span Mean 30.18 55.86 108.3 0.8612 68.69 1.403 Range Min 26.86 52.98 96.1 0.0637 63.28 1.171 Max 32.03 59.90 124.7 1.6630 74.75 1.782

TABLE 13 Droplet Size Distribution at 3 cm for sample stored at 40 degrees C., Upright position, 5M DSD 3 cm Dv(10) Dv(50) Dv(90) % D(4, 3) 40° C.-U (μm) (μm) (μm) <10μ (μm) Span Mean 26.75 56.64 120.3 0.9120 66.53 1.651 Range Min 26.22 55.44 116.8 0.7907 65.09 1.612 Max 27.33 58.02 122.7 0.9900 67.94 1.689

TABLE 14 Droplet Size Distribution at 6 cm for sample stored at 40 degrees C., Upright position, 5M DSD 6 cm Dv(10) Dv(50) Dv(90) % D(4, 3) 40° C.-U (μm) (μm) (μm) <10μ (μm) Span Mean 32.87 63.39 121.7 1.3128 71.44 1.390 Range Min 31.62 59.93 111.7 0.6002 66.68 1.280 Max 35.85 79.44 174.7 1.5100 94.26 1.748

TABLE 15 Droplet Size Distribution at 3 cm for sample stored at 40 degrees C., Horizontal position, 5M DSD 3 cm Dv(10) Dv(50) Dv(90) % D(4, 3) 40° C.-H (μm) (μm) (μm) <10μ (μm) Span Mean 26.08 55.51 116.1 0.8906 64.59 1.619 Range Min 24.86 51.65 104.2 0.7230 59.27 1.530 Max 27.12 58.59 126.6 1.0880 69.05 1.710

TABLE 16 Droplet Size Distribution at 6 cm for sample stored at 40 degrees C., Horizontal position, 5M DSD 6 cm Dv(10) Dv(50) Dv(90) % D(4, 3) 40° C.-H (μm) (μm) (μm) <10μ (μm) Span Mean 30.96 57.88 105.6 1.5678 63.84 1.288 Range Min 29.43 54.51 97.5 1.1350 59.57 1.195 Max 31.84 62.23 120.3 1.7230 70.09 1.429

TABLE 17 Plume Geometry at 3 cm for sample stored at 40 degrees C., Upright position, 5M Spray Pattern 3 cm Dmin Dmax Ovality 40° C.-U (mm) (mm) Ratio Mean 12.8 20.0 1.584 Range Min 11.6 17.2 1.289 Max 13.6 24.7 2.043

TABLE 18 Plume Geometry at 6 cm for sample stored at 25 degrees C., Horizontal position, 5M Spray Pattern 6 cm Dmin Dmax Ovality 25° C.-H (mm) (mm) Ratio Mean 21.4 29.1 1.362 Range Min 20.2 27.1 1.228 Max 22.5 32.0 1.511

TABLE 19 Plume Geometry at 3 cm for sample stored at 25 degrees C., Horizontal position, 5M Spray Pattern 3 cm Dmin Dmax Ovality 25° C.-H (mm) (mm) Ratio Mean 13.6 19.5 1.436 Range Min 13.0 18.0 1.382 Max 14.2 21.1 1.580

TABLE 20 Plume Geometry at 6 cm for sample stored a 25 degrees C., Upright position, 5M Spray Pattern 6 cm Dmin Dmax Ovality 25° C.-U (mm) (mm) Ratio Mean 21.3 30.1 1.421 Range Min 19.9 26.7 1.244 Max 22.3 33.4 1.679

TABLE 21 Plume Geometry at 3 cm for sample stored at 25 degrees C., Upright position, 5M Spray Pattern 3 cm Dmin Dmax Ovality 25° C.-U (mm) (mm) Ratio Mean 14.4 19.1 1.320 Range Min 13.2 17.1 1.212 Max 15.9 22.3 1.426

TABLE 22 Plume Geometry at 3 cm for sample stored at 40 degrees C., Horizontal position, 5M Spray Pattern 3 cm Dmin Dmax Ovality 40° C.-H (mm) (mm) Ratio Mean 13.0 18.3 1.415 Range Min 12.3 16.1 1.180 Max 13.9 21.3 1.662

TABLE 23 Plume Geometry at 6 cm for sample stored at 40 degrees C., Upright position, 5M Spray Pattern 6 cm Dmin Dmax Ovality 40° C.-U (mm) (mm) Ratio Mean 20.8 32.2 1.578 Range Min 18.3 25.3 1.151 Max 22.2 43.2 2.317

TABLE 24 Plume Geometry at 6 cm for sample stored at 40 degrees C., Horizontal position, 5 M Spray Pattern 6 cm Dmin Dmax Ovality 40° C.-H (mm) (mm) Ratio Mean 21.5 29.4 1.371 Range Min 19.8 27.1 1.253 Max 23.3 32.5 1.639

TABLE 25 Droplet Size Distribution at 3 cm for sample stored at 25 degrees C., Upright position, 6M DSD 3 cm Dv(10) Dv(50) Dv(90) % D(4, 3) 25° C.-U (μm) (μm) (μm) <10μ (μm) Span Mean 26.22 57.53 121.8 0.5523 67.25 1.652 Range Min 24.63 50.98 104.4 0.0000 59.18 1.544 Max 27.73 68.01 148.6 0.9883 79.42 1.783

TABLE 26 Droplet Size Distribution at 6 cm for sample stored at 25 degrees C., Upright position, 6M DSD 6 cm Dv(10) Dv(50) Dv(90) % D(4, 3) 25° C.-U (μm) (μm) (μm) <10μ (μm) Span Mean 31.87 62.59 119.9 1.1915 70.21 1.405 Range Min 29.24 58.74 111.6 0.8993 65.79 1.282 Max 33.93 66.29 133.7 1.4090 75.92 1.528

TABLE 27 Droplet Size Distribution at 3 cm for sample stored at 25 degrees C., Horizontal position, 6M DSD 3 cm Dv(10) Dv(50) Dv(90) % (D(4, 3) 25° C.-H (μm) (μm) (μm) <10μ (μm) Span Mean 24.55 50.03 101.6 0.8918 57.62 1.538 Range Min 22.88 46.53 91.7 0.0000 52.75 1.476 Max 25.64 52.39 109.5 1.3350 61.24 1.633

TABLE 28 Droplet Size Distribution at 6 cm for sample stored at 25 degrees C, Horizontal position, 6M DSD 6 cm Dv(10) Dv(50) Dv(90) D(4,3) 25° C.H (μm) (μm) (μm) % <10μ (μm) Span Mean 29.58 56.85 105.2 1.3818 62.82 1.323 Range Min 28.53 51.57 89.4 1.0870 55.73 1.178 Max 30.75 60.69 116.4 1.6780 67.86 1.434

TABLE 29 Droplet Size Distribution at 3 cm for sample stored at 40 degrees C., Upright position, 6M DSD 3 cm Dv(10) Dv(50) Dv(90) % D(4, 3) 40° C.-U (μm) (μm) (μm) <10μ (μm) Span Mean 27.60 58.79 125.9 0.4862 69.31 1.669 Range Min 26.50 52.85 111.3 0.0000 62.36 1.579 Max 29.11 65.51 140.0 0.7686 76.44 1.729

TABLE 30 Droplet Size Distribution at 6 cm for sample stored at 40 degrees C., Upright position, 6M DSD 6 cm Dv(10) Dv(50) Dv(90) % D(4,3) 40° C.-U (μm) (μm) (μm) <10μ (μm) Span Mean 33.68 67.20 131.3 1.0200 76.03 1.450 Range Min 32.54 63.80 118.0 0.8835 70.69 1.314 Max 35.01 70.75 141.2 1.4480 80.26 1.543

TABLE 31 Droplet Size Distribution at 3 cm for sample stored at 40 degrees C., Horizontal position, 6M DSD 3 cm Dv(10) Dv(50) Dv(90) % D(4, 3) 40° C.-H (μm) (μm) (μm) <10μ (μm) Span Mean 27.75 55.42 114.3 0.0005 64.60 1.559 Range Min 26.47 52.01 104.6 0.0000 60.13 1.475 Max 29.22 59.01 124.9 0.0019 69.62 1.621

TABLE 32 Droplet Size Distribution at 6 cm for sample stored at 40 degrees C., Horizontal position, 6M DSD 6 cm Dv(10) Dv(50) Dv(90) % D(4, 3) 40° C.-H (μm) (μm) (μm) <10μ (μm) Span Mean 34.33 63.86 118.0 0.9685 70.95 1.309 Range Min 32.47 60.19 110.1 0.0624 66.54 1.251 Max 37.21 68.17 129.6 1.5090 76.88 1.363

TABLE 33 Plume Geometry at 3 cm for sample stored at 25 degrees C., Upright position, 6 M Spray Pattern 3 cm Dmin Dmax Ovality 25° C.-U (mm) (mm) Ratio Mean 14.0 20.8 1.489 Range Min 13.4 17.9 1.300 Max 14.5 23.1 1.664

TABLE 34 Plume Geometry at 6 cm for sample stored at 25 degrees C., Upright position, 6 M Spray Pattern 6 cm Dmin Dmax Ovality 25° C.-U (mm) (mm) Ratio Mean 20.3 30.3 1.497 Range Min 19.1 27.4 1.320 Max 21.1 33.6 1.705

TABLE 35 Plume Geometry at 3 cm for sample stored at 25 degrees C., Horizontal position, 6 M Spray Pattern 3 cm Dmin Dmax Ovality 25° C.-H (mm) (mm) Ratio Mean 14.0 21.4 1.549 Range Min 12.9 19.8 1.276 Max 15.7 23.9 1.852

TABLE 36 Plume Geometry at 6 cm for sample stored at 25 degrees C., Horizontal position, 6M Spray Pattern 6 cm Dmin 25° C.-H (mm) Dmax (mm) Ovality Ratio Mean 20.2 32.3 1.599 Range Min 18.8 28.4 1.390 Max 21.3 37.7 1.808

TABLE 37 Plume Geometry at 3 cm for sample stored at 40 degrees C., Upright position, 6M Spray Pattern 3 cm Dmin 40° C.-U (mm) Dmax (mm) Ovality Ratio Mean 14.9 19.2 1.284 Range Min 13.8 17.3 1.155 Max 15.5 20.8 1.399

TABLE 38 Plume Geometry at 6 cm for sample stored at 40 degrees C., Upright position, 6M Spray Pattern 6 cm Dmin 40° C.-U (mm) Dmax (mm) Ovality Ratio Mean 21.3 27.5 1.296 Range Min 19.8 26.5 1.194 Max 22.8 29.3 1.427

TABLE 39 Plume Geometry at 3 cm for sample stored at 40 degrees C., Horizontal position, 6M Spray Pattern 3 cm Dmin 40° C.-H (mm) Dmax (mm) Ovality Ratio Mean 14.6 22.5 1.547 Range Min 13.9 20.8 1.430 Max 16.0 24.8 1.781

TABLE 40 Plume Geometry at 6 cm for sample stored at 40 degrees C., Horizontal position, 6M Spray Pattern 6 cm Dmin 40° C.-H (mm) Dmax (mm) Ovality Ratio Mean 21.5 29.4 1.371 Range Min 19.8 27.1 1.253 Max 23.3 32.5 1.639

TABLE 41 Plume Geometry at 3 cm (width and angle) 3 cm Width (mm) Angle (°) Mean 27.9 49.9 Range Min 25.5 46.1 Max 30.8 54.3

TABLE 42 Plume Geometry at 6 cm (width and angle) 6 cm Width (mm) Angle (°) Mean 40.2 37.0 Range Min 36.0 33.4 Max 43.9 40.2

Example 6: Further Buprenorphine Formulations

TABLE 43 Further Buprenorphine Formulations Formulation #14 #15 #16 #17 #18 Buprenor- 0.0813 0.1625 0.325 0.65 1.3 phine HCl BHA 0.01 0.01 0.01 0.01 0.01 BHT 0.005 0.005 0.005 0.005 0.005 L-Menthol 0.05 0.05 0.05 0.05 0.05 Ethanol 55 55 55 55 55 Propylene 5 5 5 5 5 Glycol Purified 39.8537 39.7725 39.61 39.285 38.635 Water Citric Acid QS to pH QS to pH QS to pH QS to pH QS to pH Anhydrous Sodium QS to pH QS to pH QS to pH QS to pH QS to pH Hydroxide Nitrogen Sparging/ Sparging/ Sparging/ Sparging/ Sparging/ Overlay Overlay Overlay Overlay Overlay

Buprenorphine formulations of Table 43 were all stable upon preparation.

Example 7: Further Buprenorphine/Naloxone Formulations

TABLE 44 Further Buprenorphine/Naloxone Formulations Formulation #19 #20 #21 #22 Buprenorphine HCl 8.39 5.554 2.84 1.42 Naloxone 2.37 1.57 0.804 0.402 L-Menthol 0.05 0.05 0.05 0.05 Edetate Disodium 0.005 0.005 0.005 0.005 Dihydrate Sodium Ascorbate 0.02 0.02 0.02 0.02 Ethanol 55 55 55 55 Propylene Glycol 5 5 5 5 Water 29.165 32.801 36.281 38.103

Buprenorphine/naloxone formulations of Table 44 were all stable upon preparation.

Example 5: Method of Treatment of Pain Using Buprenorphine

Specifications of the Study

This was a multicenter, randomized, double-blind, multiple-dose, placebo-controlled study evaluating the efficacy and safety of three dosing regimens of Buprenorphine Sublingual Spray (0.5 mg three times daily (“tid”), 0.25 mg tid, or 0.125 mg tid), and/or matching placebo in subjects with moderate to severe postoperative pain after bunionectomy, 322 subjects were randomized, 298 subjects completed the study, and 24 discontinued for various reasons (9 to lack of efficacy; 14 due to nausea and emesis; and 1 for non-related hypotension); and one lost to follow-up.

The study lasted four months and comprised 4 periods: The Screening Period (Days −28 to −1), the Surgical Period (Day 0), the Treatment Period (48 hours; Days 1 to 3) and the Follow-up Period (Days 5 to 9).

The measurements of pain intensity and pain relied were conducted at Time 0 (i.e., at 5, 15, 30, and 45 minutes, and 1, 1.5, 2, 3, 4, 5, 6, 7, 8, 12, 16, 20, 24, 32, 40, and 48 hours).

As agreed with the U.S. Food and Drug Administration (“FDA”), the primary efficacy endpoint in this study was the Summed Pain Intensity Difference relative to baseline over a period of 48 hours (SPID-48). The patient assessment of pain intensity utilized a numeric pain scale (11-point scale with 0=no pain to 10=worst possible pain).

The secondary variables were as follows:

-   -   SPID over 0 to 4 hours (SPID-4), over 0 to 8 hours (SPID-8), and         over 0 to 24 hours (SPID-24) after Time 0;     -   Time to onset of analgesia (measured as time to perceptible pain         relief confirmed by meaningful pain relief using the 2-stopwatch         method); and     -   Pain intensity difference (PID) at each scheduled time point         after Time 0.

The disposition of subjects is depicted in the flow chart in FIG. 1.

Results

The primary efficacy endpoint was statistically significant at all doses studied. The Buprenorphine Sublingual Spray 0.5 mg tid demonstrated the largest reduction in SPID-48 and was statistically significant to placebo (p<0.0001). The 0.25 mg tid and 0.125 mg tid doses also demonstrated statistically significant reductions in SPID-48 (p=0.0108 and p=0.0120, respectively). All treatments were generally well tolerated.

FIG. 2 depicts a chart of Numeric Rating Scale (NRS) Summed Pain Intensity Difference (SPID) at 4, 8, 24 and 48 hours.

Table 45 below describes NRS SPID over 0 to 48 hours (NRS SPID-48) for intention-to-treat (ITT) population.

TABLE 45 Summary of SPID-48 (ITT Population) Buprenorphine Sublingual Spray Placebo 0.5 mg TID 0.25 mg TID 0.125 mg TID Statistic (N = 79) (N = 81) (N = 80) (N = 82) n 75 72 75 77 mean (SD) 93.40 (85.063) 182.81 (107.349) 125.75 (102.247) 135.84 (114.040) CV 91.07 58.72 81.31 83.95 median 84.0 181.0 98.0 130.3 min, max −77.7, 377.8  −17.8, 414.6 −55.5, 399.0 −90.5, 399.4 Least square mean(SE)^(a) 89.40 (10.109) 171.33 (10.316)  125.58 (10.101)  124.85 (9.944)  95% CI 69.50, 109.29 151.02, 191.63 105.70, 145.46 105.28, 144.43 Comparison Least square mean difference (SE)^(a) 95% CI P-value^(a) 0.5 mg vs. placebo 81.93 (14.283) 53.82, 110.04 <0.0001 0.25 mg vs. placebo 36.18 (14.099) 8.43, 63.93 0.0108 0.125 mg vs. placebo 35.46 (14.020) 7.86, 63.05 0.0120 Note: SPID-48 = Summary of Pain Intensity Differences over 48 hours, CV = coefficient of variation, TID = three times daily. ^(a)Least square means, standard errors(SE), confidence interval(CI) and p-values are from an ANCOVA model with factors for treatment, site and baseline pain intensity.

Table 46 below describes NRS SPID over 0 to 24 hours (NRS SPID-24) for ITT population.

TABLE 46 Summary of SPID-24 (ITT Population) Buprenorphine Sublingual Spray Placebo 0.5 mg TID 0.25 mg TID 0.125 mg TID Statistic (N = 79) (N = 81) (N = 80) (N = 82) n 75 73 76 77 mean (SD) 26.61 (42.855) 80.93 (53.234) 49.21 (48.223) 49.90 (56.899) CV 161.02 65.78 97.98 114.02 median 21.0 83.4 43.2 48.3 min, max −46.3, 161.8 −30.8, 196.9 −40.9, 177.5 −62.8, 175.9 Least square mean(SE)^(a) 24.16 (5.001)  75.67 (5.066)  48.85 (4.962)  44.17 (4.920)  95% CI 14.31, 34.00 65.70, 85.64 39.08, 58.62 34.49, 53.86 Comparison Least square mean difference (SE)^(a) 95% CI P-value^(a) 0.5 mg vs. placebo 51.51 (7.041) 37.66, 65.37 <0.0001 0.25 mg vs. placebo 24.69 (6.952) 11.01, 38.38 0.0004 0.125 mg vs. placebo 20.02 (6.937)  6.37, 33.67 0.0042 Note: SPID-24 = Summary of Pain Intensity Differences over 24 hours, CV = coefficient of variation, TID = three times daily. ^(a)Least square means, standard errors(SE), confidence interval(CI) and p-values are from an ANCOVA model with factors for treatment, site and baseline pain intensity.

Table 47 below describes NRS SPID over 0 to 8 hours (NRS SPID-8) for ITT population.

TABLE 47 Summary of SPID-8 (ITT Population) Buprenorphine Sublingual Spray Placebo 0.5 mg TID 0.25 mg TID 0.125 mg TID Statistic (N = 79) (N = 81) (N = 80) (N = 82) n 77 78 78 78 mean (SD) 2.14 (13.589) 19.18 (19.606) 8.63 (17.661) 8.71 (18.707) CV 633.82 102.20 204.61 214.72 median 0.8 19.2 7.5 6.1 min, max −25.1, 36.3 −26.7, 65.3  −23.3, 63.1  −27.8, 57.2  Least square mean(SE)^(a) 1.32 (1.851)  17.57 (1.835)  8.26 (1.843)  7.08 (1.837)  95% CI −2.32, 4.97 13.96, 21.18 4.63, 11.89 3.47, 10.70 Comparison Least square mean difference (SE)^(a) 95% CI P-value^(a) 0.5 mg vs. placebo 16.24 (2.582)  11.16, 21.32  <0.0001 0.25 mg vs. placebo 6.93 (2.579) 1.86, 12.01 0.0076 0.125 mg vs. placebo 5.76 (2.582) 0.68, 10.84 0.0265 Note: SPID-8 = Summary of Pain Intensity Differences over 8 hours, CV = coefficient of variation, TID = three times daily. ^(a)Least square means, standard errors(SE), confidence interval(CI) and p-values are from an ANCOVA model with factors for treatment, site and baseline pain intensity.

Table 48 below describes NRS SPID over 0 to 4 hours (NRS SPID-4) for ITT population.

TABLE 48 Summary of SPID-4 (ITT Population) Buprenorphine Sublingual Spray Placebo 0.5 mg TID 0.25 mg TID 0.125 mg TID Statistic (N = 79) (N = 81) (N = 80) (N = 82) n 78 81 80 80 mean (SD) 1.29 (8.466) 8.48 (10.089) 4.15 (9.230) 4.59 (10.637) CV 656.18 119.05 222.41 231.79 median 0.0 8.2 4.0 2.9 min, max −20.3, 25.3 −19.1, 30.2  −17.2, 27.1  −22.2, 28.5  Least square mean(SE)^(a) 0.67 (1.036) 7.70 (1.013)  3.67 (1.023) 3.74 (1.020)  95% CI −1.37, 2.70 5.71, 9.69 1.66, 5.68 1.73, 5.75 Comparison Least square mean difference (SE)^(a) 95% CI P-value^(a) 0.5 mg vs. placebo 7.03 (1.436) 4.21, 9.86 <0.0001 0.25 mg vs. placebo 3.00 (1.439) 0.17, 5.84 0.0377 0.125 mg vs. placebo 3.07 (1.441) 0.24, 5.91 0.0337 Note: SPID-4 = Summary of Pain Intensity Differences over 4 hours, CV = coefficient of variation, TID = three times daily. ^(a)Least square means, standard errors(SE), confidence interval(CI) and p-values are from an ANCOVA model with factors for treatment, site and baseline pain intensity.

Table 49 shows time of onset analgesia for investigator initiated trials (IIT) population.

TABLE 49 Time to Onset of Analgesia (ITT Population) Buprenorphine Sublingual Spray Placebo 0.5 mg TID 0.25 mg TID 0.125 mg TID (N = 79) (N = 81) (N = 80) (N = 82) Number (%) of sujects with onset of analgesia 27 (34.2) 53 (65.4) 37 (46.3) 36 (43.9) Number (%) of subjects censored 52 (65.8) 28 (34.6) 43 (53.8) 46 (56.1) Time (minutes) from first dose to onset of analgesia^(a) 25^(th) percentile (95% CI) 5.0 (4.0, 83.0) 6.0 (5.0, 15.0) 13.0 (5.0, 29.0) 15.0 (6.0, 27.0) Median (95% CI) NE 43.0 (21.0, 64.0) NE (43.0, NE) NE (41.0, NE) 75^(th) percentile (95% CI) NE NE (101.0, NE) NE NE Mean (SE) 58.4 (4.11) 146.4 (21.35) 58.7 (4.46) 58.3 (4.30) Comparison P-value^(b) 0.5 mg vs. placebo 0.0010 0.25 mg vs. placebo 0.3018 0.125 mg vs. placebo 0.3701 ^(a)Percentile estimates and confidence intervals (CI) are from a Kaplan-Meier analysis. ^(b)P-value from a log-rank test of each treatment arm vs. placebo Note: TID = three times daily, NE = not estimable. Denominator for percentages is the number of subjects per treatment group in the ITT population. Time to onset of analgesia is the time when the first stopwatch is stopped given that the second stopwatch is stopped. If the second stopwatch is not stopped, time will be censored at the time of the second dose of study drug or the use of rescue medication, whichever comes first. If both stopwatches are not stopped, time will be censored at the time of the second dose of study drug or the use of rescue medication whichever comes first.

FIG. 3 depicts a chart of time of onset of analgesia for placebo, 0.5 mg tid, 0.25 mg tid and 0.125 tid doses.

Table 50 is a representation of mean pain intensity differences by timepoint.

TABLE 50 Placebo 0.5 mg TID 0.25 mg TID 0.125 mg TID Timepoint Statistic (N = 79) (N = 81) (N = 80) (N = 82) 5 minutes n 79 81 80 82 mean (SD) 0.3 (1.06) 0.5 (1.15) 0.3 (1.01) 0.3 (0.75) 15 minutes n 79 81 80 82 mean (SD) 0.6 (1.76) 0.4 (1.39) 0.6 (1.56) 0.6 (1.55) 30 minutes n 79 81 80 82 mean (SD) 0.7 (2.15) 0.6 (1.65) 0.7 (2.12) 0.7 (2.18) 45 minutes n 79 81 80 81 mean (SD) 0.6 (2.38) 1.1 (2.08) 0.9 (2.13) 1.0 (2.41) 1 hour n 79 81 80 81 mean (SD) 0.6 (2.58) 1.5 (2.40) 1.0 (2.37) 1.1 (2.62) 1.5 hours n 78 81 80 80 mean (SD) 0.6 (2.77) 2.1 (2.72) 1.2 (2.58) 1.2 (2.91) 2 hours n 78 81 79 80 mean (SD) 0.5 (2.77) 2.4 (3.07) 1.2 (2.62) 1.3 (3.05) 3 hours n 78 81 80 80 mean (SD) 0.2 (2.35) 2.7 (3.09) 1.3 (2.95) 1.3 (3.22) 4 hours n 78 81 80 80 mean (SD) −0.1 (2.13)  2.6 (3.26) 0.9 (3.14) 1.1 (3.21) 5 hours n 77 80 79 80 mean (SD) −0.4 (2.08)  2.6 (3.06) 0.8 (3.14) 1.2 (3.32) 6 hours n 78 78 79 79 mean (SD) 0.2 (2.16) 3.1 (3.16) 1.1 (3.16) 1.1 (3.19) 7 hours n 77 79 79 78 mean (SD) 0.4 (2.11) 3.0 (3.06) 1.3 (2.88) 0.9 (2.93) 8 hours n 77 78 78 78 mean (SD) 0.5 (2.10) 2.5 (3.06) 1.2 (2.78) 0.7 (2.73) 12 hours n 75 78 77 78 mean (SD) 1.0 (2.50) 3.7 (2.78) 2.2 (2.88) 2.0 (3.40) 16 hours n 75 76 76 77 mean (SD) 0.9 (2.11) 3.4 (2.65) 1.9 (2.63) 1.9 (3.16) 20 hours n 75 75 76 77 mean (SD) 2.1 (2.90) 4.3 (2.70) 3.2 (2.69) 3.1 (3.07) 24 hours n 75 73 76 77 mean (SD) 2.2 (2.59) 4.0 (2.64) 3.0 (2.72) 3.2 (2.98) 32 hours n 75 72 75 77 mean (SD) 2.4 (2.48) 3.9 (2.89) 2.9 (2.80) 3.4 (2.90) 40 hours n 75 71 75 77 mean (SD) 2.5 (2.21) 3.9 (2.81) 3.2 (2.58) 3.3 (2.80) 48 hours n 75 72 75 77 mean (SD) 3.5 (2.60) 4.9 (2.33) 3.5 (3.00) 4.1 (2.89)

The conclusions are as follows:

Primary Efficacy

The largest pain reduction (NRS SPID-48) was observed for the 0.5 mg TID BSS group.

Statistically significantly larger reductions in NRS SPID-48 compared to placebo for the 0.5 mg TID BSS p-value: <0.0001. The largest reduction in NRS SPID-48 compared to placebo was observed for the 0.5 mg TID BSS treatment group.

Secondary Efficacy

Largest pain reductions (NRS SPID-4, NRS SPID-8, and NRS SPID-24) were observed for 0.5 mg TID BSS group (p-value: <0.0001). Secondary time points at 4, 8 and 24 hours SPID were all statistically significantly different. 

What is claimed is:
 1. A sublingual spray formulation comprising: buprenorphine, a pharmaceutically acceptable salt thereof or a derivative thereof is at an amount from about 0.08% to about 1.3% w/w; water as a solvent is at an amount from about 38% to about 40% w/w; a cosolvent consisting of a mixture of ethanol in an amount of 55% w/w and propylene glycol in an amount of about 5% w/w; an antioxidant consisting of a mixture of butylated hydroxyanisole (BHA) in an amount of about 0.01% w/w and butylated hydroxytoluene (BHT) in an amount of about 0.005% w/w; and menthol at an amount of about 0.05% w/w, wherein w/w denotes weight by total weight of the formulation.
 2. The sublingual spray formulation of claim 1 that is capable of producing a droplet size distribution wherein greater than 98% of the composition particles are greater than 10 microns in diameter during administration.
 3. The sublingual spray formulation of claim 1 that is capable of producing a droplet size distribution wherein: the mean Dv(10) is from about 10 to about 30 microns during administration; the mean Dv(50) is from about 30 to about 80 microns during administration; and the mean Dv(90) is from about 80 to about 200 microns during administration.
 4. The sublingual spray formulation of claim 1 that is capable of producing a spray span ((Dv90−Dv10)/Dv50) of from about 1.2 to about 3.3.
 5. The sublingual spray formulation of claim 1 that is capable of producing a spray plume that has an ovality ratio of from about 1.1 to 2.4.
 6. The sublingual spray formulation of claim 1 that is capable of producing a spray plume width that is from about 25 to about 45 millimeters during administration and a spray plume angle that is from about 30 to about 55 degrees during administration.
 7. The sublingual spray formulation of claim 1 that is capable of producing a D(4,3) of 55 to 95 microns.
 8. The sublingual spray formulation of claim 1 that is capable of producing a droplet size distribution wherein the C_(max) (ng/mL) of buprenorphine is from about 0.6 to about 0.8 following administration.
 9. The sublingual spray formulation of claim 1 that is capable of producing a droplet size distribution wherein the T_(max) of buprenorphine is from about 1.5 to about 1.9 hours following administration.
 10. A method of treating pain comprising administering the sublingual spray formulation of claim 1 to a patient in need thereof.
 11. A method of treating opioid dependence comprising administering the sublingual spray formulation of claim 1 to a patient in need thereof. 